Pressed Rapeseed Oil Research Articles

Effect of different pretreatment techniques on quality characteristics, chemical composition, antioxidant capacity and flavor of cold-pressed rapeseed oil

This study investigated the effects of different pretreatment techniques (microwave heating, infrared heating, oven heating and enzymatic methods) on the quality of cold-pressed rapeseed oil (CPRO) with commercially available first-grade pressed rapeseed oil (CFO) as a control. The results showed that CPRO is more nutritionally valuable than CFO while meeting the quality standard without refining. Microwave heating pretreatment's cold-pressed rapeseed oil (MHO) exhibited a higher oil yield (70.83 ± 0.40 %), a higher trace active ingredient content (tocopherol 53.79 ± 0.19 mg/100 g, phytosterol 726.98 ± 4.14 mg/100 g, and polyphenol 87.09 ± 0.08 mg GAE/100 g), and a stronger antioxidant capacity. Correlation analysis and multiple linear regression analysis indicated that antioxidant capacity was mainly related to the content of α-tocopherol and polyphenols. Microwave heating promoted the degradation of the Maillard reaction and glucosinolates, significantly improving the flavor of CPRO. Therefore, microwave heating is a promising pretreatment technology for the production of high-quality CPRO.

Influence of two-stage harvesting on the properties of cold-pressed rapeseed (Brassica napus L.) oils

Rapeseed (Brassica napus L.) harvesting method is critical since it significantly determines the seed yield, oil quality, and industrial efficiency. This study investigated the influences of harvesting methods on the quality of cold-pressed rapeseed oil of two varieties. Oil color, peroxide value (POV), tocopherol content, fatty acid composition, and polarity of total polyphenols (PTP) contents of two rapeseed varieties in Huanggang and Xiangyang were compared through artificially simulated combined harvesting and two-stage harvesting. Results showed significant differences in the quality of rapeseed oil between the two harvesting methods. The red value (R-value), POV, total tocopherol contents, linoleic and linolenic acid content, and PTP content of the pressed rapeseed oil prepared by the combined harvesting method were about 27.6, 5.7, 15.8, 2.0, 0.5, and 28.6% lower than those of the oil produced from the two-stage harvesting method, respectively. Xiangyang and Huayouza62 performed better in the two regions and two varieties, respectively. To sum up, the rapeseed oil obtained 41–44 days after final flowering of combined harvesting, 35 days after final flowering, and six days of post-ripening of the two-stage harvesting had the best quality.

Analysis of Volatile Compounds Changes during the Oxidation of Pressed Rapeseed Oil

Volatile flavor components of first-grade pressed rapeseed oil (S1) and fourth-grade pressed rapeseed oil (S2) subjected to accelerated oxidation test at 60 ℃ were profiled by means of headspace solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS) coupled with electronic nose (E-nose) technology, followed by correlation analysis with quality indicators. The results showed that the acid value of S1 and S2 was related to acid compounds. The content of aldehyde compounds had an important correlation with the degree of oxidation deterioration. The peroxide value of S1 was generally higher than that of S2. After 20 d of accelerated oxidation, S1 had a higher anisidine value than S2. S1 had a high oxidation rate in the early stage of oxidation, and S2 had a high oxidation rate in the later stage of oxidation. It showed that the deterioration degree of S1 was higher than that of S2. The main volatile components of rapeseed oil during accelerated oxidation were mainly aldehydes. The characteristic flavor components of S1 accelerated oxidation for 20 days were nonanal, decanal, 2,4-decadienal and 2-decanone. The characteristic flavor components of S2 accelerated oxidation for 20 days were (E)-2-decenal. The E-nose radar chart could distinguish unoxidized oil and oxidized oil, as well as the difference in flavor components in the early and late stages of oxidation. The content of (E)-2-decenal, (E)-2-nonenal, octanal and 2-undecenal were related to the peroxide value, anisidine value and total oxidation value of S1. The content of nonanal, (E,E)-2-4 decenal, (E)-2-decenal, (E)-2-nonenal, decanal, octyl aldehyde and heptanal were related to the peroxide value, anisidine value and total oxidation value of S2. Volatile components can be used as indicators to monitor the oxidation degree of rapeseed oil during storage.

Effect of Deep Frying of Potatoes and Tofu on Thermo-Oxidative Changes of Cold Pressed Rapeseed Oil, Cold Pressed High Oleic Rapeseed Oil and Palm Olein.

One of the commonly used food preparation methods is frying. Fried food is admired by consumers due to its unique taste and texture. Deep frying is a process of dipping food in oil at high temperature, usually 170–190 °C, and it requires a relatively short time. The aim of this study was to analyze the thermo-oxidative changes occurring during the deep frying of products such as potatoes and tofu in cold pressed rapeseed oils and palm olein. Cold pressed rapeseed oil from hulled seeds (RO), cold pressed high oleic rapeseed oil from hulled seeds (HORO), and palm olein (PO) (for purposes of comparison) were used. Characterization of fresh oils (after purchase) and oils after 6, 12, and 18 h of deep frying process of a starch product (potatoes) and a protein product (tofu) was performed. The quality of oils was analyzed by determining peroxide value, acid value, p-anisidine value, content of carotenoid and chlorophyll pigments, polar compounds, smoke point, color (CIE L*a*b*), fatty acids content and profile, calculation of lipid nutritional quality indicators, and oxidative stability index (Rancimat). Cold pressed high oleic rapeseed oil was more stable during deep frying compared to cold pressed rapeseed oil, but much less stable than palm olein. In addition, more thermo-oxidative changes occurred in the tested oils when deep frying the starch product (potatoes) compared to the deep frying of the protein product (tofu).

Current state and development trends of spring rape market in the agricultural sector of Krasnoyarsk krai

This article is devoted to the general survey of spring rape (colza) market in the Krasnoyarsk Krai to 2019, figures on the dynamics of crop area and average rapeseed yield in the region are presented. The main perspectives of further development of rapeseed cultivation within the territory of the region are viewed. The scheme of comprehensive processing of rape oilseeds for the enterprises of the agricultural sector in the Krasnoyarsk Krai which cultivate spring rape (colza) for seeds and produce pressed rapeseed oil is offered.

Low vs high field 1h Nmr spectroscopy for the detection of adulteration of cold pressed rapeseed oil with refined oils

Cold pressed rapeseed oil (CPRO) is a relatively recent development in rapeseed processing, which produces a quality product with a high market value. High field NMR (400 MHz) is a well-established tool in food analysis, while low-field NMR (60 MHz) is much less studied. This study aims to establish the effectiveness of both techniques in identifying binary adulteration in CPRO. Three adulteration scenarios were investigated: a) CPRO and refined rapeseed oil (RRO); b) CPRO and refined sunflower oil (RSO); and c) CPRO and RRO or RSO. A range of classification techniques were trialled as well as partial least squares regression to gauge predictive quantification performance. The 400 MHz NMR achieved classification rates of 100% in the scenarios with a single adulterant, and 93% in the multiple adulterant scenario. The 60 MHz NMR produced lower but still encouraging classification rates (RSO 92%; RRO 85%; both RRO and RSO 87%).

Detection of Refined Sunflower and Rapeseed Oil Addition in Cold Pressed Rapeseed Oil Using Mid Infrared and Raman Spectroscopy

In this study, a new screening technique for the detection of two types of oil adulterants in cold pressed rapeseed oil is investigated. The calibration models built with four different multivariate classifiers (SIMCA, PLS‐DA, LDA‐KNN, and LDA‐SVM) are based on spectral fingerprints from either FT‐IR and Raman instruments from authentic pure oils and in‐house admixtures of the oils involved. When refined sunflower oil is the adulterant, both FT‐IR and Raman produce effective models with high sensitivity of 86% and 93% respectively. When refined rapeseed oil is the adulterant the sensitivity decreases. This is explained by the chemical differences of the two adulterants. PLS‐R quantification analysis estimates minimum detection levels of 15% (Raman) and 9% (FT‐IR) when refined sunflower oil is the adulterant, and 22% (Raman) and 64% (FT‐IR) when refined rapeseed oil is the adulterant. This initial study shows the potential of Raman spectroscopy to be utilized for the screening of cold pressed rapeseed oil authenticity.Practical Applications: It has been well documented in the past that high‐value edible oils can be easily adulterated with lower cost oils for economic gain. Although the cold pressed rapeseed oil industry has not experienced such fraud, it would be prudent to have analytical techniques available to authenticate genuine oils quickly. This would further strengthen cold pressed rapeseed oil's reputation as a product free from substitutional fraud. These calibration models can tool the industry and regulatory bodies with a screening method to detect authenticity in realistic levels.A feasibility study regarding cold pressed rapeseed oil adulteration is investigated. Cold pressed rapeseed oil is adulterated with either refined rapeseed oil or refined sunflower oil and spectra is acquired using either Raman or FT‐IR spectroscopy. A library of spectra is gathered which includes pure cold pressed rapeseed oil and cold pressed rapeseed oil admixtures of varying concentrations. Chemometric analysis is carried out on the dataset with both classification and quantification techniques. The optimum instrument‐chemometric pairings for cold pressed rapeseed oil authentication are discussed.

O3 An in vitro study on the anti-cancer properties of rapeseed pomace extracts

Natural products have recently been exploited as alternative sources of cancer chemo-preventative agents. Induction of cell cycle arrest and apoptosis, and prevention of carcinogenesis and cancer progression are some of the mechanisms studied in cell systems and animal models. By-products from rapeseed oil extraction processes, however, have not been studied before: this study aims to assess the potential anti-cancer properties of extracts from rapeseed pomace (RSP), the by-product of cold pressed rapeseed oil production. RSP was extracted using accelerated solvent extraction (ASE) with different ethanol (EtOH) to water (dH 2 O) ratios: 50:50 EtOH:dH 2 O RSP extract showed significantly higher concentrations in Gallic Acid Equivalent (Folin Ciocalteu assay) compared to controls, and a significant increase in free radical scavenging properties (DPPH assay) was observed for 50:50 and 20:80 EtOH:dH 2 O RSP extracts. Moreover, extracts’ anticancer properties were assessed in a breast cancer cell line, MDA-MB-231. The three RSP extracts did not show cell cytotoxicity at concentrations ⩽1 mg/ml; however, at 2.5 mg/ml, 50:50 EtOH:dH 2 O RSP extract significantly decreased cell viability by 72% and, at 5 mg/ml, all extracts were cytotoxic. Cell treatment with 50:50 EtOH:dH 2 O RSP extract did not induce further DNA strand breaks (COMET assay) compared to untreated controls; however, an increase was measured with both 80:20 and 20:80 EtOH:dH 2 O RSP extracts. The anti-cancer properties of RSP extracts demonstrated in this study warrant further investigation and, potentially, open new avenues for the identification of chemo-preventative agents and reutilisation/revalorisation of rapeseed pomace.

Characterization and comparison of UK, Irish, and French cold pressed rapeseed oils with refined rapeseed oils and extra virgin olive oils

Various chemical parameters were used to characterize a wide range of cold pressed rapeseed oils and to contrast the findings with refined rapeseed and extra virgin olive oil. There were significant differences between cold pressed rapeseed oils regarding almost all measured parameters. Volatile composition analysis showed that hexanal, 3‐methyl pentane and 1‐butene, 4‐isothiocyanato were the most abundant compounds. There was no correlation between volatile compounds and geographical region of cold pressed rapeseed oils. French cold pressed rapeseed oils were found in exhibit significantly higher antioxidant activity levels than cold pressed rapeseed oils from other regions. Refined rapeseed oil was found to have a higher antioxidant activity but have significantly lower levels of phenolic acids (0.008 mg/kg oil) than cold pressed rapeseed oil (0.46 mg/kg oil). These phenolic acids appear to be important for oxidative stability as cold pressed rapeseed oil was more stable under heat stress than refined rapeseed oil. Olive oil was the most stable under heat stress, largely due to its comparatively high saturated fat content. Antioxidant potential, phenolic acids and peroxide values were found to be the main factors differentiating cold pressed rapeseed oil from refined rapeseed oil.Practical applications: Cold pressed rapeseed oil is a relatively new oil to the market and this study is the first to examine oils available to the British, Irish and French consumers. It shows the compositional variation of oils on the market by analyzing many parameters important for oil quality and consumer palatability. Antioxidant behavior and phenolic acid identification indicate potential health benefiting properties. This research also compares cold pressed rapeseed oils with market competitors which allows for clear comparison of these widely used edible oils.Cold pressed rapeseed oil is made by mechanically crushing rapeseeds at a low temperature, followed by filtering and bottling the oil. This work investigates the chemical composition of cold pressed rapeseed oil, along with its antioxidant capacity and stability under heat stress. Cold pressed rapeseed oil is also compared to market competitors; refined rapeseed oil and extra virgin olive oil.

Pre‐processing effects on cold pressed rapeseed oil quality indicators and phenolic compounds

This study exposed seven rapeseed cultivars to various seed pre‐processing practices. The aim of the study was to investigate the effect of pre‐processing on cold pressed rapeseed oil parameters associated with health and flavor. Results showed the pre‐processing in this study were not a significant factor regarding oil quality. The total phenols of oils from unprocessed seeds ranged from 0.005–2.468 mg/kg oil. The phenolic acids investigated in the roasted group averaging 10.386 mg/kg and the microwaved group averaging 8.015 mg/kg. Part of this increase was due to the formation of canolol in these groups. Microwaved and roasted groups had significantly higher DPPH radical scavenging potential than the other groups. The thermal pre‐processing techniques also significantly altered the volatile composition of the roasted and microwaved groups. Ultrasound pre‐processing had no significant impact on any of the parameters studied.Practical applications: The regulations surrounding cold pressing means that there are restrictions regarding extraction procedures and the treatment of the oil after cold pressing. This means that the main opportunity to alter cold pressed oil is pre‐processing of the seed (in this case rapeseed). Pre‐processing of rapeseed can alter the composition of cold pressed rapeseed oil without impinging on cold pressing regulations. This study shows how pre‐processing techniques can increase the attributes of cold pressed rapeseed oil in relation to antioxidant activity and phenolic acids. This work shows that pre‐processing has a much greater effect on these parameters than varietal selection.Rapeseed pre‐processing and subsequent analysis of cold pressed rapeseed oil compounds associated with flavor and health.

Lipid components and oxidative status of selected specialty oils

Many vegetable oils are marketed as specialty oils because of their retained flavors, tastes and distinct characteristics. Specialty oil samples which were commercially produced and retailed were purchased from local superstores in Reading, UK, and Uppsala, Sweden and profiled for detailed lipid composition and oxidative status. These oil samples include: almond, hazelnut, walnut, macadamia nut, argan, avocado, grape seed, roasted sesame, rice bran, cold pressed, organic and cold pressed, warm pressed and refined rapeseed oils. The levels of PV were quite low (0.5-1.3mEq O2 /kg) but AV and Rancimat values at 100°C (except for rapeseed oils) varied considerably at (0.5-15.5) and (4.2-37.0 h) respectively. Macadamia nut oil was found to be the most stable oil followed by argan oil, while walnut oil was the least stable. Among the specialty oils, macadamia nut oil had the lowest (4%) and walnut oil had the highest (71%) level of total PUFA. The organic cold pressed rapeseed oil had considerably lower PUFA (27%) compared with other rapeseed oils (28- 35%). In all the samples, α- and γ- tocopherols were the major tocopherols; nut oils had generally lower levels. Total sterols ranged from 889 to 15,106 µg/g oil. The major sterols were β-sitosterol (61-85%) and campesterol (6-20%). Argan oil contained schottenol (35%) and spinasterol (32%). Compared with literature values, no marked differences were observed among the differently processed, organically grown or cold pressed rapeseed oils and other specialty oils in this study.

Characteristics of a tractor engine using mineral and biodiesel fuels blended with rapeseed oil

One of the most unfavourable characteristics of crude vegetable oil when used as the fuel is the high viscosity. To improve this weakness, oil can be blended with mineral diesel or biodiesel fuels. This study was designed to evaluate how the use of mineral diesel or biodiesel blend with cold pressed rapeseed (Brassica napus) oil affects the engine power, torque and fuel consumption. A tractor equipped with direct injection, water cooling system and three-cylinder diesel engine was used for the experiment. Fuels used were standard diesel fuel (diesel), rapeseed oil methyl ester - biodiesel (B100) and their mixtures with 10, 30 and 50 vol. % of cold pressed rapeseed oil (RO). Increased portion of RO in diesel fuel blends had almost no effect on the torque measured on the tractor PTO shaft; it however decreased the maximal power. Fuel blends with B100 and rising RO content (up to 50%) gave a positive correlation with maximal torque and power. By increasing the portion of RO from 0 to 50%, the minimal specific fuel consumption increased by 6.65% with diesel and decreased by 2.98% with B100 based fuel.

Analysis of carotenoids and vitamin E in selected oilseeds, press cakes and oils

AbstractCarotenoids and vitamin E in oils from the market – 6 rapeseed and 6 sunflower oils, half of each cold pressed and refined – and in the oils of rape, sunflower, flax and safflower as well as the respective seeds and press cakes from a local oil mill were quantified by HPLC. Furthermore, a photometric determination of carotenoid content was tested and checked against the chromatographic method. In the cold pressed oils minor amounts of xanthophylls (all‐E)‐lutein and (all‐E)‐zeaxanthin were determined. With exception of traces of (all‐E)‐β‐carotene in cold‐pressed rapeseed oil this provitamin A active compound did not occur. Cold pressed rapeseed oils contained 0.5–1.5 mg total carotenoids/100 g which was manifold the content of the further oils. Vitamin E was found in all vegetable oils at plant‐typic tocopherol patterns. The photometric determination of carotenoids resulted in significantly higher concentrations compared to the HPLC. This overestimation bases on the carotenoid pattern which was validated by comparison with known high‐carotenoid materials, i.e. maize flour with an abundant amount of xanthophylls and carrots with an abundant amount of carotenes.

Effect of enzymatic and hydrothermal treatments of rapeseeds on quality of the pressed rapeseed oils: part II. Oil yield and oxidative stability

Response surface methodology was used to evaluate the quantitative effects of three independent variables: rapeseed moisture content (MC), enzymes dosage (ED) and conditioning temperature ( T) on rapeseed oil yield (OY), efficiency of pressing (EP), and oxidative stability (OS). The highest OY (16.4%) and EP (42.8%) were obtained from pectolytic enzyme (0.1%) treated seeds (MC = 9%, T = 90 °C). The highest OS (12.6 h) was found for oil pressed from rapeseeds heated at 120 °C (MC = 11%), after the cellulolytic enzyme treatment. Results of OY, EP and OS determinations correlate with the predicted values calculated from the partial cubic models (PCMs) equations ( R 2 = 0.9995, 0.9994, 0.9974 for the cellulolytic enzyme-treated oils and 0.9900, 0.9900, 0.9990 for the pectolytic enzyme-treated oils). The predicted optimum MC = 9.5% and 8.6%, ED = 0.06% and 0.1%, T = 91.2 °C and 90.1 °C resulted in OY = 15.5% and 16.5%, EP = 40.4% and 43.0% for rapeseed oils from seeds treated with cellulolytic and pectolytic enzymes. OS values (12.6 h and 11.8 h) at the optimum conditions of MC = 11.0% and 10.1%, ED = 0.04% and 0.08%, T = 120.0 °C and 119.9 °C for the cellulolytic and pectolytic enzyme-treated oils were also calculated using PCM. Moreover, scanning electron microscopy revealed structural changes in the rapeseed after enzymatic treatment.

Effect of enzymatic and hydrothermal treatments of rapeseeds on quality of the pressed rapeseed oils: Part I: Antioxidant capacity and antioxidant content

Response surface methodology was used to evaluate the quantitative effects of three independent variables: rapeseed moisture content, concentration of the added enzymes and conditioning temperature, on the antioxidant capacity and total phenolic, tocopherol, and phospholipid contents in the enzyme-treated rapeseed oils. The highest antioxidant capacity (1220.0, 964.8 μmol TE/100 g) total phenolic (83.3, 74.0 mg SA/100 g) and phospholipid (12,532, 12,376 mg/kg) contents reveal two rapeseed oils extruded from seeds contained 11% moisture, treated with cellulolytic and pectolytic enzymes (0.05%), respectively, and heated at 120 °C. However, the highest content of total tocopherols was determined in rapeseed oils pressed from seeds with 7% moisture, after addition of cellulolytic (0.05%) and pectolytic (0.1%) enzymes, heated at 90 and 105 °C, respectively. Total phenolic and phospholipid contents in the enzyme-treated rapeseed oils correlated significantly ( p < 0.0000001) with antioxidant capacities of oils ( R 2 = 0.8710 and 0.6581, respectively). Experimental results of the antioxidant capacity, total phenolic, tocopherol and phospholipid contents were close to the predicted values calculated from the polynomial response surface models equations ( R 2 = 0.9727, 0.9870, 0.8390 and 0.9706 for the cellulolytic enzyme-assisted rapeseed oils and R 2 = 0.9148, 0.9489, 0.9426 and 0.9479 for the pectolytic enzyme-assisted rapeseed oils). The optimum rapeseed moisture content, enzyme concentration and conditioning temperature for the cellulolytic and pectolytic enzyme-treated rapeseed oils were 11% and 9.7%, 0.08% and 0.1%, and 120 °C, respectively.

Effect of Hydrothermal Treatment of Rapeseed on Antioxidant Capacity of the Pressed Rapeseed Oil

AbstractResponse surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables, rapeseed moisture content and conditioning temperature, on the antioxidant capacity (AC) and total phenolic (TPC), tocopherol (TTC), and phosphorus contents (PC) in the pressed rapeseed oils. The mean AC results for the crude rapeseed oils ranged from 199.8 to 947.2 µmolTE/100 g. TPC and PC in the crude rapeseed oils correlated significantly (P &lt; 0.01) and positively with AC of oils (R2 = 0.9498 and 0.4396, respectively). The experimental results of AC, TPC, and PC were close to the predicted values calculated from the polynomial response surface model equations (R2 = 0.9801, 0.9747 and 0.9165, respectively). The effect of oil processing temperature on AC and TPC was about 1.5 times greater than the effect of moisture level in rapeseed.

The DGF Rapeseed Oil Award – A tool to improve the quality of virgin edible rapeseed oil

AbstractVirgin cold pressed rapeseed oils are becoming more popular in Germany. They are characterized by their specific taste and smell which resembles asparagus, cabbage or fresh, green vegetables in contrast to the refined oils. The quality of virgin rapeseed oils on the German market is very heterogeneous, resulting in a problem for the consumer to choose an oil with a pleasant taste and smell. The German Society for Fat Science (DGF) created in 2006 the DGF Rapeseed Oil Award for virgin rapeseed oils of excellent flavour in order to highlight good products and to bring the sensory quality of virgin rapeseed oil more into the focus of the producers. The paper describes the reasons, procedure and the performance of the DGF Rapeseed Oil Award and discusses the question whether the medal is suitable to improve the quality of the oils in the market and to thereby strengthen the confidence of the consumer in the product. Additionally the results of the years 2006 and 2007 are shown.

Performance of direct-injection off-road diesel engine on rapeseed oil

This article presents the comparative bench testing results of a naturally aspirated, four stroke, four cylinder, water cooled, direct injection Diesel engine operating on Diesel fuel and cold pressed rapeseed oil. The purpose of this research is to study rapeseed oil flow through the fuelling system, the effect of oil as renewable fuel on a high speed Diesel engine performance efficiency and injector coking under various loading conditions. Test results show that when fuelling a fully loaded engine with rapeseed oil, the brake specific fuel consumption at the maximum torque and rated power is correspondingly higher by 12.2 and 12.8% than that for Diesel fuel. However, the brake thermal efficiency of both fuels does not differ greatly and its maximum values remain equal to 0.37–0.38 for Diesel fuel and 0.38–0.39 for rapeseed oil. The smoke opacity at a fully opened throttle for rapeseed oil is lower by about 27–35%, however, at the easy loads its characteristics can be affected by white coloured vapours. Oil heating to the temperature of 60 °C diminishes its viscosity to 19.5 mm 2 s −1 ensuring a smooth oil flow through the fuel filter and reducing the brake specific energy consumption at light loads by 11.7–7.4%. Further heating to the temperature of 90 °C offers no advantages in terms of performance. Special tests conducted with modified fuel injection pump revealed that coking of the injector nozzles depends on the engine performance mode. The first and second injector nozzles that operated on pure oil were more coated by carbonaceous deposits than control injector nozzles that operated simultaneously on Diesel fuel.